Orally effective ion chelators

ABSTRACT

Compounds are described of the general formula: ##STR1## wherein: R 1  is acyl of the formula --C(═O)--R 5  ; R 2 , R 3 , and R 4  are each selected from the group consisting of hydrogen and acyl of the formula: 
     
         --C(═O)--R.sub.5 
    
     wherein R 5  is selected from the group consisting of alkyls, substituted alkyls, alkenyls, substituted alkenyls, cycloalkyls, substituted cycloalkyls, arylalkylenes, substituted arylalkylenes, alkylenecycloalkyls, alkylene substituted cycloalkyls, alkynyls substituted alkynyls, aryls and substituted aryls, wherein R 2 , R 3  and R 4  are selected such that at least one of R 2 , R 3  and R 4  is an acyl. 
     When R 2 , R 3  and R 4  include one or more acyls that are not identical to the acyl of R 1 , these compounds of formula I are novel compounds. The invention also includes processes to produce the compounds of formula I. 
     Compounds of formula I complex and/or chelate tissue tri-valent ions, especially iron (Fe +++ ), when administered to a human being, and are therefore useful in therapy in the treatment of diseases in which tissue ion levels in the body have increased or toxic levels. These diseases include, for example, thalassemia major, sideroachrestic anemic, Blackfan-Diamond anemia, aplastic anemia, sickel cell anemia, hemolytic anemias and hemosiderosis brought about by multiple blood transfusions including treatment for the anemia accompanying conditions requiring kidney dialysis.

This is a continuation of Ser. No. 574,482, filed Jan. 26, 1984, nowU.S. Pat. No. 4,684,482, issued Aug. 4, 1987.

BACKGROUND OF THE INVENTION

The present invention is concerned with the preparation of compounds,compositions and methods which are useful for treating diseases in humanbeings which are a result of a body tri-valent ion (i.e. Fe⁺⁺⁺) overloadstate. Iron overload diseases include thalassemia major, sideroachresticanemia, Blackfan-Diamond anemia, aplastic anemia, sickle cell anemia,other hemolytic anemias, and a number of other diseases and conditionsin which hemosiderosis (a focal or general increase in tissue ironstores without associated tissue damage) occurs. One type ofhemosiderosis occurs in most patients after multiple blood transfusionshave occurred. Another type of hemosiderosis occurs as the result of thetreatment of an anemia found in kidney damaged patients where dialysisis used to remove toxic wastes. Treatment of zothese conditions hasgenerally involved the administration of a chelating agent having aselective affinity for tissue Fe⁺⁺⁺ ion which can then be excreted asthe iron chelate.

The ideal chelating agent for the reduction of tissue iron should haveat least the following attributes:

1. Have high selectivity with respect to iron binding;

2. Be essentially metabolically inert;

3. Be essentially non-toxic;

4. Be inexpensive to produce; and

5. Be capable of oral administration.

Over the years a number of approaches have been investigated which havesome of these attributes. The current drug of choice is deferoxamine, acompound obtained from the microorganism Strephemyces pilosus.Deferoxamine has the following structure: ##STR2##

This material meets the aforementioned criteria except for oralavailability. Deferoxamine (as the methanesulfonate salt) has been shownto be most effective when it is delivered parenterally via slowcontinuous (about an 8-12 hour period) subcutaneous infusion using aportable infusion pump, i.e., a battery powered syringe pump.

This administration route is particularly difficult in view of thewidespread occurrance of the disease, thalassemia major, found in thepopulation in countries bordering on the Mediterranean Sea and extendingeastward through the Middle East, India to Southeast Asia, and in sicklecell anemia which is prevalent in the populations in Africa.

The present invention concerns certain acyl derivatives of deferoxaminewhich are effective iron chelators when administered orally.

Some compounds related to the compounds of the present invention aredescribed in the literature by H. Bickel, et al. in Helvitica ChimicaActa, Vol. 46, No. 153, pp 1385-1389, published in 1963 and theirrelated U.S. Pat. No. 3,247,197, which are incorporated herein byreference.

The focus of these references are the preparation of N-acyl trihydroxyderivatives of deferoxamine which have the structure: ##STR3## whereinR₁ may be an acyl group. These references mention tetra acyl materials,i.e., materials of the formula: ##STR4## wherein the R groups are eachacetyls, as intermediates in the production of their focus compounds.These references do not teach the use of tetra-acyl materials in bodyiron removal applications nor do they suggest that the tetra-acylmaterial would be effective when orally administered in theseapplications.

U.S. Pat. Nos. 3,118,823 and 3,153,621 are concerned with iron chelatesof deferoxamine, which are used as growth factors. Additional referencesof interest in this art include Bickel, et al , Helvitica Chimica Acta,Vol. 43, pp. 2118 ff and 2129 ff, published in 1960; and V. Prelog andWalser, Helvitica Chimica Acta, Vol. 45, pp 631 ff, published in 1962.Finally, D. E. Green and T. B. Okarma briefly reported on studies on thepreparation of the tetra-acyl derivatives of deferoxamine and thebiological properties of these derivatives. (See Abstracts, 186th AnnualAmerican Chemical Society Meeting, Aug. 28-Sept. 2, 1983, Washington,D.C., Abstract No. MEDI 56).

SUMMARY OF THE INVENTION

The present invention concerns a group of di-, tri- and tetra-acylatedderivatives of deferoxamine, which are useful in the treatment of thediseases or conditions cited earlier. The invention is particularlyuseful in that its compounds are orally administered, absorbed from thedigestive system into the body and cleaved to produce deferoxamine inthe body.

In one aspect, this invention relates to compounds of the generalformula: ##STR5## wherein:

R₁ is an acyl of the formula --(C═O)--R₅ ;

R₂, R₃, and R₄ are each selected from the group consisting of hydrogenand acyls of the formula:

    --C(═O)--R.sub.5

wherein R₅ is selected from the group consisting of alkyls, substitutedalkyls, alkenyls, substituted alkenyls, cycloalkyls, substitutedcycloalkyls, arylalkylenes, substituted arylalkylenes,alkylenecycloalkyls, alkylene substituted cycloalkyls, alkynyls,substituted alkynyls, aryls and substituted aryls.

R₂, R₃ and R₄ are selected such that at least one of R₂, R₃ and R₄ is anacyl of the formula --C(═O)--R₅ different than R₁.

When R₂, R₃ and R₄ include one or more acyls of formula --C(═O)--R₅,wherein R₅ is not identical to the R₅ of the acyl of R₁, these compoundsof formula I are novel compounds and represent another aspect of thisinvention.

Compounds of formula I are prodrug forms of deferoxamine which liberatedeferoxamine in the body to complex and/or chelate iron for subsequentexcretion when administered to a human being, and are therefore usefulin therapy in the treatment of diseases in which iron levels in the bodyhave elevated or toxic levels. These diseases include, for example,thalassemia major, sideroachrestic anemia, Blackfan-Diamond anemia,aplastic anemia, sickle cell anemia, hemolytic anemias and hemosiderosisbrought about by multiple blood transfusions or such condition whenbrought about by treatment of an anemia found in kidney-damaged patientsundergoing renal dialysis.

Another aspect of the present invention relates to compounds of formulaI as is described herein which liberate deferoxamine in the body togenerally chelate any trivalent metal, such as iron, aluminum, chromiumand the like, for subsequent excretion, which is useful in the treatmentof diseases or conditions in which the elevated levels of metal in thebody cause or exacerbate disease conditions. The compounds of formula Iare useful as oral pharmaceuticals in the treatment of Alzheimer's andrelated diseases in which elevated aluminum levels have been found inthe body, particularly the brain.

Thus other aspects of the invention concern pharmaceutical preparationsincorporating the compounds of formula I, dosage forms thereof andmethods of treatment of the aforementioned conditions employing thesepreparations and/or dosage forms.

Another aspect of this invention is a process for the preparation of thecompounds of formula I, as is described in greater detail hereinafter.

DETAILED DESCRIPTION OF THE INVENTION Definitions

"Acyl" is defined to refer to a group having the structure, --(C═O)--R₅,wherein R₅ is selected from the group consisting of alkyls, substitutedalkyls, alkenyls, substituted alkenyls, cycloalkyls, substitutedcycloalkyls, arylalkylenes, substituted arylalkylenes,alkylenecycloalkyls, alkylene substituted cycloalkyls, alkynyls,substituted alkynyls, aryls and substituted aryls.

"Acylating agent" refers to a compound containing the group --(C═O)--R₅which can react and insert an "acyl" into deferoxamine. Representativeagents include, for example, acyl halides, acyl anhydrides, mixed acylanhydrides and mixtures thereof. When different acylating agents areemployed herein they may include acylating agents which are in differentcatagories, e.g., alkyl acyl (acetyl chloride) and alkenyl acyl(methacryloyl chloride) or may include different acylating agents withinthe same category (e.g., acetyl chloride and propionyl chloride, etc.)or by substitution of one to three protons, e.g., propionyl chloride and2-chloropropionyl chloride.

"Alkyl" refers to a branched or unbranched saturated hydrocarboncontaining 1 to 25 carbon atoms, such as, for example, methyl, ethyl,n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-heptyl,i-heptyl, n-octyl, nonyl, decyl, undecyl, tridecyl, pentadecyl,heptadecyl, pentacosanyl and the like.

"Substituted alkyl" refers to an "alkyl" group, wherein at positions onthe linear or branched structure one to three protons have been replacedby a group such as alkoxyl or halogen.

"Alkenyl" refers to a linear or branched unsaturated hydrocarbon groupcontaining from 2 to 25 carbon atoms, such as, for example, ethenyl,propenyl, butenyl (1- and 2-), isobutenyl, hexenyl, heptenyl, nonenyl,undecenyl, dodecenyl, nonadecenyl, cosenyl, pentacosenyl and the like.

"Substituted alkenyl" refers to an "alkenyl" where at positions on thelinear or branched structure, one to three protons have been replaced bya group such as alkoxyl or halogen.

"Cycloalkyl" refers to a cyclic alkyl structure containing 3 to 25carbon atoms. The cyclic structure may have alkyl substituents at anyposition. Representative groups include cyclopropyl, 4-methylcyclohexyl,cyclooctyl, cyclohexadecyl, cyclopentacosanyl and the like.

"Substituted cycloalkyl" refers to a "cycloalkyl" where at positions onthe group, one to three protons have been replaced by a group, such asalkoxyl, alkyl or halogen.

"Arylalkylene" refers to a group containing an "aryl" attached throughan "alkylene." Representative groups include benzyl (phenylmethylene),phenylethylene (phenethyl), phenyldecylene, naphthylmethylene,naphthyl-2-methylethylene and the like.

"Substituted arylalkylene" refers to an "arylalkylene" containing a"substituted aryl" moiety. Representative groups include2-methylphenylmethylene, 4-chlorophenylethylene, 4-bromophenylpropylene,6-methoxynaphthylmethylene, 6-chloronaphthyldecylene and the like.

"Alkylenecycloalkyl" refers to a group wherein the alkylene portion is asaturated hydrocarbon which contains 1 to 10 carbon atoms. One end ofwhich is attached to the --C(═O)-- group and the other end of which isattached to a "cycloalkyl" group. Representative groups includeethylenecyclopropyl, propylenecyclohexyl, 2-methylpropylenecyclodecyl,decylenecyclopentacosanyl and the like.

"Alkylene substituted cycloalkyl" refers to an alkylenecycloalkyl havinga "substituted cycloalkyl" moiety. Representative groups includemethylene-2-chlorocyclopropyl, ethylene-4-methylcyclohexyl,decylene-4-hydroxycyclodecyl, decylene-2-bromocyclopentacosanyl and thelike.

"Alkynyl" refers to a branched or linear aliphatic hydrocarbon grouphaving a --C.tbd.C-- moiety which contains from 2 to 25 carbon atoms,such as for example, ethynyl, propynyl, isohexynyl, heptynyl,pentadecynyl, pentacosynyl and the like.

"Substituted alkynyl" refers to an "alkynyl" group, where at positionson the linear or branched structure, one to three protons have beenreplaced by a group such as alkoxy or halogen.

"Halo" or "halogen" refers to fluoro, chloro, bromo or iodo, usually asa substitutent replacing a hydrogen atom in an organic group.

"Alkylene" refers to a saturated linear or branched hydrocarbonstructure containing 1 to 10 carbon atoms which has two points ofattachment to other functional groups. Representative "alkylenes"include methylene (--CH₂ --), ethylene (--CH₂ --CH₂ --),2-methylpropylene [--CH₂ --CH(CH₃)--CH₂ --], hexylene, decylene and thelike.

"Aryl" refers to a carbon-containing aromatic structure having 6 to 14carbon atoms. Representative groups include phenyl, naphthyl,phenanthryl and the like.

"Substituted aryl" refers to an "aryl" wherein at 1 to 3 positions onthe aromatic ring, one to three protons have been replaced by anothergroup, such as alkyl, alkoxyl or halogen.

The compounds of this present invention are generally named according tothe IUPAC or Chemical Abstracts nomenclature. Thus, deferoxamine may benamed N'-[5-[[4-[[-5-(acetylhydroxamino)pentyl]amino]-1,4-dioxobutyl]hydroxyamino]pentyl]-N-(5-aminopentyl)-N-hydroxybutanediamide;orN-[5-[3-[(5-aminopentyl)hydroxylcarbamoyl]propionamido]-pentyl]-3-[[5-(N-hydroxyacetamido)pentyl]-carbamoyl]propionohydroxamicacid; or 1-amino-6,17-dihydroxy-7,10,18,21-tetraoxo-27-(N-acetylhydroxylamino)-6,11,17,22-tetraazaheptaeicosane.

Because of the obvious complexity of the names for the substitutedstructures of deferoxamine, a shorthand form based upon the last writtenname above is used for the present invention. Therefore, the 1-aminogroup, when substituted by acyl (R₁ --), is designated as N-acyl(--N--R₁). The hydroxamic acid hydrogen at the 6-position, whensubstituted by acyl (R₂ --) is designated as O-acyl (--O--R₂). Thehydroxamic acid hydrogen at the 17-position, when substituted by acyl(R₃ --) is designated as O-acyl (--O--R₃). And the hydroxamic acidhydrogen of the "27-(N-acetylhydroxylamino)" when substituted by acyl(R₄ --) is designated as (--O--R₄).

Thus in formula I, when R₁ is acetyl, and R₂, R₃, and R₄ are eachn-octanoyl, the compound name is N-acetyl-0,0,0-trioctanoyldeferoxamine.When R₁ is isovaleryl, R₂ is acetyl (i.e., R₅ here is --CH₃), R₃ isbutyryl (R₅ here is --CH₂ CH₂ CH₃) and R₄ is n-octanoyl [R₅ here is -CH₂(CH₂)₅ CH₃ ], the compound name isN-isovaleryl-0,0,0-acetylbutyryl-n-octanoyldeferoxamine. If the aminogroup or any combination of the hydroxamic acid groups areunsubstituted, the unsubstituted position is designated as N-hydrogen(N--H or --O--hydrogen (--O--H), respectively reading R₂, R₃, and R₄,from left to right for the compound of formula I.

In defining the size of organic groups, i.e., R₅ -- herein, "lower"groups (e.g., lower alkyl) contain 1 to 7 carbon atoms, "intermediate"groups e.g., intermediate alkenyl) contain 8 to 15 carbon atoms, and"higher" groups (e.g., higher alkyl) contain from 16 to 25 carbon atoms.

DETAILED DESCRIPTION AND PRESENTLY PREFERRED EMBODIMENTS

Although not understood with certainty, it appears that the best resultsare obtained when the total number of carbon atoms in the groups R₁, R₂,R₃ and R₄ of formula I is between 10 and 50, preferably between 12 and40, and especially between 14 and 30. Structures of formula I where thetotal of the carbon atoms in the groups R₁, R₂, R₃, and R₄ are less than9 have not yet achieved good results, perhaps because deferoxaminederivatives having these smaller acyls are not absorbed through themembranes of the digestive tract. Structures of formula I wherein thetotal of the carbon atoms of R₁, R₂, R₃ and R₄ is greater than 63 havenot yet achieved good results, perhaps because the molecules are notsufficiently soluble in the fluids within the digestive tract to beabsorbed into the body as the prodrug to be cleaved to producedeferoxamine.

The compounds of formula I, prepared according to the proceduresdescribed herein and which achieve good results in reducing the amountof tissue iron in a human being, are found in Table 1.

                                      TABLE I                                     __________________________________________________________________________     ##STR6##                                                                     DEFEROXAMINE DERIVATIVES                                                      Compound     Number of Carbon Atoms                                           Group        R.sub.1                                                                          R.sub.2            R.sub.3                                                                          R.sub.4                                 __________________________________________________________________________     1           2  3                  3  3                                        2           2  4                  4  4                                        3           2  5                  5  5                                        4           2  6                  6  6                                        5           2  7                  7  7                                        6           2  8                  8  8                                        7           3  3                  3  3                                        8           3  4                  4  4                                        9           3  5                  5  5                                       10           3  6                  6  6                                       11           3  8                  8  8                                       12           4  3                  3  3                                       13           4  4                  4  4                                       14           4  5                  5  5                                       15           4  6                  6  6                                       16           4  8                  8  8                                       17           5  3                  3  3                                       18           5  4                  4  4                                       19           5  5                  5  5                                       20           5  6                  6  6                                       21           5  8                  8  8                                       22           6  3                  3  3                                       23           6  4                  4  4                                       24           6  5                  5  5                                       26           6  6                  6  6                                       27           6  8                  8  8                                       28           7  3                  3  3                                       29           7  4                  4  4                                       30           7  5                  5  5                                       31           7  6                  6  6                                       32           7  7                  7  7                                       33           8  3                  3  3                                       34           8  4                  4  4                                       35           8  5                  5  5                                       36           8  6                  6  6                                       37           8  8                  8  8                                       __________________________________________________________________________

Preferred compounds of formula I found in the "Compound Groups" in TableI are those compounds where R₅ is alkyl, and especially preferred arethe linear alkyl compounds. Preferred groups include Compound Groups 7,13, 19, 26, 32 and 37, wherein R₁, R₂, R₃, and R₄ contain the samenumber of carbon atoms. Particularly preferred are those groups whereinR₅ is alkyl, especially lower alkyl. These compounds where R₅ is alkylare preferred to be orally administered to treat the iron relateddiseases described herein.

preferred compounds of formula I also include those wherein up to two ofR₂, R₃, and R₄ are hydrogen. See, for example, Table II.

                                      TABLE II                                    __________________________________________________________________________     ##STR7##                                                                     DEFEROXAMINE DERIVATIVES                                                      Compound     Number of Carbon Atoms.sup.a                                     Group        R.sub.1                                                                          R.sub.2            R.sub.3                                                                          R.sub.4                                 __________________________________________________________________________     1           2  8                  8  0                                        2           2  8                  0  8                                        3           2  0                  8  8                                        4           2  0                  0  8                                        5           2  0                  8  0                                        6           2  8                  0  0                                        7           4  4                  4  0                                        8           4  6                  0  6                                        9           4  0                  8  8                                       10           5  5                  5  0                                       11           5  0                  6  6                                       12           6  6                  6  0                                       13           6  5                  5  0                                       14           6  8                  8  0                                       15           8  8                  8  0                                       16           8  8                  0  8                                       17           8  0                  8  8                                       18           8  4                  4  0                                       19           8  5                  5  0                                       20           8  6                  6  0                                       21           6  4                  0  4                                       22           5  4                  0  4                                       23           4  5                  0  5                                       24           3  3                  3  0                                       25           3  4                  4  0                                       26           3  5                  0  5                                       27           3  4                  0  4                                       28           2  4                  0  4                                       29           2  5                  5  0                                       30           2  6                  0  6                                       __________________________________________________________________________     .sup.a When the carbon atom number is 0, the group R.sub.2, R.sub.3, and      R.sub.4 contains 0 carbon atoms, and is a hydrogen (H).                  

Because of the present difficulty of separating some of the isomers ofthe products described in Table I and Table II, this invention includesmixtures of compounds which would normally be expected in the reactionproducts described in the examples below. For instance, if in theCompound Group in Table II, numbers 15, 16 and 17 are present asreaction products of the acylation of deferoxamine using a limitedamount of R₁ =8 [(i.e., R₅ =7 carbon atoms) acylating agent].

Presently preferred embodiments of the present invention include thosecompounds of formula I wherein R₁, R₂, R₃, and R₄ are identical alkylacyl groups, especially lower alkyl acyls. Especially preferred arethose compounds where acyl is --C(═O)--R₅, and R₅ is n-propyl, n-butyl,t-butyl, n-pentyl, n-hexyl or n-heptyl.

Another embodiment of the present invention includes those compounds offormula I as described herein, except that when R₁ is acyl of formula--C(═O)--R₅ and R₅ is alkyl, R₂, R₃, and R₄ as a group are not each acylof formula --C(═O)--R₅ wherein R₅ is the identical alkyl of R.sub..

Another embodiment of the present invention includes those compounds offormula I as described herein, except that when R₁ is acyl of formula--C(═O)-- R₅ and R₅ is alkenyl, R₂, R₃, and R₄ as a group are not eachacyl of formula --C(═O)--R₅ wherein R₅ is the identical alkenyl of R₁.

Especially preferred embodiments of the present invention also includethose compounds of formula I wherein R₁ is acetyl and R₂, R₃, and R are--(C═O)--R₅, wherein R₅ is alkyl, particularly lower alkyl, especiallypropyl, i-butyl, t-butyl or n-heptyl.

Additional preferred embodiments include those compounds of formula Iwherein R₁ is --C(═O)--R₅ wherein R₅ is intermediate alkyl, and R₂, R₃,and R₄ are --C(═O)--R₅ wherein R₅ in each is lower alkyl. A particularlypreferred embodiment is the compound where R₁ is --(C═O)--R₅ and R₅ isundecyl, and R₂, R₃, and R₄ are each --C(═O)--R₅ wherein R₅ is propyl.

An additional embodiment of the present invention describes apharmaceutical composition useful for treating one or more diseases orconditions o in a human being, related to excess iron in the bloodand/or tissue, which comprises using a therapeutically effective amountof a compound of formula I in admixture with a pharmaceuticallyacceptable excipient. Preferred embodiments include the pharmaceuticalcomposition containing the compound of formula I wherein R₁, R₂, R₃, andR₄ are identical acyl groups. Particularly preferred are those compoundscontaining 2 to 8 carbon atoms in each acyl, especially, acyls of theformula --C(═O)--R₅, where R₅ is lower alkyl as is defined herein.

Additional preferred embodiments include the pharmaceutical compositionsincluding the compound of formula I wherein R₁ is one acyl group of theformula --C(═O)--R₅ containing 2-8 carbon atoms, particularly loweralkyl; and R₂ =R₃ =R₄ are all a different acyl group of the formula--C(═O)--R₅ wherein R₅ contains 2 to 7 carbon atoms, particularly whereR₅ is lower alkyl. Preferred compounds include those where R₁ is acetyland R₂ =R₃ =R₄ where R₅ is ethyl, n-propyl n-butyl, i-butyl, t-butyl,n-pentyl, n-hexyl, or n-heptyl. An especially preferred compound isN-acetyl-0,0,0-tri-n-octanoyldeferoxamine.

An additional embodiment of the present invention describes a method oftreating a disease or condition in a human being, related to excess ironin the blood and/or tissue which method comprises administering to asubject in need of such treatment a therapeutically effective amount ofthe compound of formula I. Preferred embodiments include the methodinvolving the compound of formula I wherein R₁, R₂, R₃, and R₄ areidentical acyl groups. Particularly preferred are those compoundscontaining 2 to 8 carbon atoms per acyl, especially, acyls of theformula --C(═O)--R₅, where R₅ is lower alkyl as is defined herein.Additional preferred embodiments include the pharmaceutical compositionincluding the compound of formula I wherein R₁ is one acyl group of theformula --C(═O)--R₅ containing 2-8 carbon atoms; and R₂ =R₃ =R₄ are alla different acyl group of the formula --C(═O)--R₅ wherein R₅ contains 2to 7 carbon atoms, particularly where R₅ is lower alkyl. Preferredcompounds include those where R₁ is acetyl and R₂ =R₃ =R₄ where R₅ isethyl, n-propyl n-butyl, i-butyl, t-butyl, n-pentyl, n-hexyl orn-heptyl. An especially preferred compound isN-acetyl-0,0,0-tri-n-octanoyldeferoxamine.

Still another embodiment of the present invention describes a processfor the preparation of the compounds of formula I which processcomprises contacting the unsubstituted deferoxamine wherein R₁, R₂, R₃,and R₄ are each hydrogen with a suitable acylating agent in the Presenceof a strong base, treating the product with a weak base to form theN-acyl-0,0,0-trihydrogendeferoxamine; and treating this material withone or more different acyating agents to form the compound of formula I.In a preferred embodiment the first suitable acylating agent is R₅--C(═O)--X or R₅ --(C═O)OC(C═O)--R₅ where R₅ contains 1 to 7 carbonatoms and X is halogen; the weak base has a pK_(b) value of about 4 to6; and the second different acylating agent is R₅ --C(═O)--X or R₅(C═O)OC(C═O)R₅ wherein R₅ contains 1 to 7 carbon atoms and X is halogen.A particularly preferred embodiment is the process wherein R₅ of thefirst acylating agent contains one carbon atom; the weak base isammonia; and in the different acylating agent R₅ contains 4 to 7 carbonatoms. An especially preferred embodiment is the process wherein thefirst acylating agent is acetyl chloride or acetic anhydride; the baseis gaseous anhydrous ammonia; and the different acylating agent isoctanoyl chloride.

process for preparation

In Reaction Sequence 1, deferoxamine (Ia), as described by M. Windholz,Ed. in The Merck Index, published by Merck Co., Inc. of Rahway, N.J. in1976 p. 374), is used as a starting material. ##STR8##

In Step 1, deferoxamine (Ia) is treated with an excess of acyl anhydridein the presence of the alkaline salt of the anhydride in an alcoholicsolvent. After about 12 to 24 hours, the solvent and acyl acid areremoved under reduced pressure to yield Ib. R₆, R₇ and R₈ independentlymay be the same or different groups as is described herein forR₅. ThusR₆ --C(═O)--X, R₇ --C(═O)--X and R₈ --C(═O)--X may also describe acylhalides which may be used as a mixture to acylate deferoxamine. If theseprocedures are used, then it is possible to convert compound of formulaIa to the compound of formula I in one step. (See Example 4 (m) and 6(m)below.) The reaction product is a mixture which may be used, as amixture, as a pharmaceutical agent, as is described herein. On the otherhand, the products may be separated by methods described herein belowand used separately.

Alternatively, deferoxamine (Ia) may be tetraacylated using an acylhalide. Deferoxamine is suspended in a solution of water/solvent (i.e.,water/dioxane, about 50/50) and the pH is adjusted to about 9 using astrongly basic solution, preferably 4 to 7N sodium hydroxide. In smallportions, the acyl halide in a solvent, such as dioxane, is addeddropwise keeping the pH at about 9. Water and a chlorinated solvent,such as chloroform, may be needed to keep the reactants in solution.Strong agitation the reaction mixture is necessary. The dioxane (andchloroform) phase is removed, washed, dried and removed in vacuo toproduce the compound of formula Ib. Step 1 and Step 3 below, using acylhalide are often referred to as the Schotten-Baumann reaction, which isdescribed in the art.

In Step 2, the compound of formula Ic is obtained by dissolving theN-acyl-0,0,0-triacyl product of formula Ib in an excess of an etherealalcoholic solvent, such as methanol, and cooling to about -20° C. to+20° C., preferably about 0° C., the reaction mixture is subsequentlysaturated with a base, preferably gaseous ammonia. After maintaining thereaction mixture at about -20° C. to +20° C., preferably at ambienttemperature, and allowed to stir for about 24 to 48 hours. The solventis decanted and the product, usually as a solid, is recovered, washedtwice with boiling hexane, and the resulting solid is and dried underreduced pressure. After recrystallization from alcohol/water solution,the product is recovered and air dried.

In Step 3, compound lc is suspended in a solution of water/solvent(i.e., water/chloroform about 50/50). The solution is adjusted to aboutpH of 9 using strong base, preferably 3-7N sodium hydroxide solution. Tothis mixture is added dropwise a solution of the acyl halide, preferablythe chloride, in a solvent such as chloroform. The pH of the solution iscontinuously monitored and is maintained at pH of 9. The layer ofchlorinated solvent is removed, washed, dried, filtered, and evaporatedin vacuo to produce a waxy crystalline product, the compound of formulaI.

Isolation and purification of the compounds and intermediates describedherein can be effected, if desired, by any suitable separation orpurification procedure such as, for example, filtration, extraction,crystallization, column chromatography, high pressure liquidchromatogrophy, thin-layer chromatography or thick-layer chromatography,dry column chromatography or a combination of these procedures. Specificillustrations of suitable separation and isolation techniques can be hadby reference to the examples herein below. Other equivalent separationor isolation procedures, however, could also be used.

In the preparation of the compounds of formula I, separation,purification, and identification of possible partially acylatedderivatives of deferoxamine is difficult, uneconomic and sometimesimpossible with present separation techniques. Therefore, this inventionincludes mixtures of compounds of formula I wherein the groups R₂, R₃,and R₄ are hydrogen or acyl as is defined herein. The mixture ofproducts is administered as part of a pharmaceutical composition to aperson in the same manner that an essentially pure compound of formula Iwould be administered.

The acyl halides and anhydrides, solvents, reagents and the likedescribed herein are available according to Chemical Sources, publishedby Directories Publishing Company, Inc., Flemington, N.J. in 1979. Thosehalides or anhydrides not available are prepared according to methodsknown or adapted from the art, see for example, R. Morrison and R. Boyd,Organic Chemistry, 3rd ed., published by the Benjamin Co. in 1973.

Utility And Administration

Administration of the compounds of this invention can be via any of theaccepted modes of administration for therapeutic agents. These methodsinclude oral, parenteral, transdermal, subcutaneous and other systemicmodes. The preferred method of administration is oral.

Depending on the intended mode, the composition may be in many forms,for example, solid, semi-solid, or liquid dosage forms, includingtablets, time release agents, pills, capsules, suspensions, solutionsand the like. The compositions will include a conventionalpharmaceutical excipient and an active compound of formula I or thepharmaceutically acceptable salts thereof and may, in addition, includeother medicinal agents, pharmaceutical agents, carriers, adjuvants,diluents, etc.

The amount of the active compound of formula I administered will, ofcourse, be dependent on the molecular weight of selected compound, thesubject being treated, the subject's weight, the severity of theaffliction, the manner of the administration and the judgment of theprescribing physician. However, an effective dose is in the range ofabout 25-200 mg/kg/day, preferably about 125 mg/kg/day. For an average70 kg human, those dosages would amount to about 1.5 to 14 g/day, orpreferably about 9 g/day.

For solid compositions, conventional nontoxic solids include forexample, pharmaceutical grades of manitol, lactose, starch, magnesiumstearate, cellulose and the like may be used. Liquid pharmaceuticallyadministratable compositions can be prepared by dissolving, dispersing,etc., a compound of formula I and optional pharmaceutical adjuvants inan excipient, such as, for example, water, glycerol, ethanol, vegetableoil and the like to form a suspension.

Actual methods of preparing such dosage forms are known, or will beapparent to those skilled in the art; see, for example, Remington'sPharmaceutical Sciences, Mack Publishing Company, Easton, Penn., 15thEdition, 1975.

The following preparations and examples serve to illustrate theinvention. They should not be construed as narrowing it, nor as limitingits scope.

EXAMPLE 1 Preparation of N-Acetyl 0,0,0-triacetyldeferoxamine

(a) Deferoxamine mesylate (13.1g) and 1.66g of anhydrous sodium acetateare dissolved in 200 ml of methanol. The methanol solution is boiled tocomplete the solution. The reaction mixture is then rapidly cooled toambient temperature and treated immediately (before crystallizationstarts) with 180 ml of acetic anhydride. The mixture is maintainedovernight (about 16 hrs) in the absence of moisture and thenconcentrated under vacuum to produce an oily residue. This residue isfreed from acetic acid by evaporation under vacuum using two portions of200 ml of butanol. The oily residue is air dried for several days toproduce 14.1 g of the N-acetyl-0,0,0-triacetyldeferoxamine. The protonmagnetic resonance spectrum is consistent with this structure;[structural unit, parts per million (ppm) downfield fromtetramethysilane (TMS) reference]:

(for C--H absorption):

--N--C--C--CH₂ --C--C--N--O--: 1.44;

--N--C--C--C--CH₂ --C--N--O--: 1.52;

--N--C--CH₂ --C--C--C--N--O--: 1.58;

CH₃ --C(═O)--N--(OCO--C--); 1.95;

CH₃ --C(═O)--NH--C--C--C--; 1.99

--C--C(═O)--N--(O--CO--CH₃); 2.17;

--N--C(═O)--CH₂ --CH₂ --(C═O)--N--; 2.56;

--C--C--CH₂ --N(--O)--(C═O)--; 3.22;

--C--(C═O)--NH--CH₂ --C--; 3.70; and

for the N--H absorption):

--C--C(═O)--NH--C--C--; 6.28.

(b) Similarily proceeding as in Subpart (a) above but substituting astoichiometrically equivalent amount of

propionyl anhydride;

butyryl anhydride;

valeryl anhydride;

isovaleryl anhydride;

octanoyl anhydride;

dodecanoyl anhydride;

palmitoyl anhydride;

stearoyl anhydride; or

hexacosanoyl anhydride

instead of acetic anhydride, there is obtained the corresponding

N-propionyl-0,0,0-tripropionyldeferoxamine;

N-butyryl-0,0,0-tributyryldeferoxamine;

N-valeryl-0,0,0-trivaleryldeferoxamine;

N-isovaleryl-0,0,0-triisovaleryldeferoxamine;

N-octanoyl-0,0,0-trioctanoyldeferoxamine;

N-dodecanoyl-0,0,0-tridodecanoyldeferoxamine;

N-palmitoyl-0,0,0-tripalmitoyldeferoxamine;

N-stearoyl-0,0,0-tristearoyldeferoxamine; or

N-hexacosanoyl-0,0,0-tri(hexacosanoyl)deferoxamine.

It is often necessary to employ larger volumes of solvents to keep thesubstituted deferoxamine in solution and to obtain more completeacylation of the three hydroxamic acids.

(c) Similarily, when proceeding as in Subpart (a) above but substitutingless than a stoichiometrically equivalent amount of the acyl anhydride,there is obtained a compound wherein the N-acyl group is formed and amixture containing less than complete acylation of the hydroxamic acidgroups of deferoxamine. Such mixtures when acetic anhydride is usedinclude the following compounds:

N-acetyl-0,0,0-hydrogendiacetyldeferoxamine and

N-acetyl-0,0,0-dihydrogenacetyldeferoxamine.

The exact positions of the acetyl and hydrogen groups on thehydroxamines is not yet established.

(d) Similarily proceeding as in Subpart (a) above but substituting astoichiometrically equivalent amount of a mixture of the followinganhydrides:

acetic anhydride, propionic anhydride, and butyric anhydride; or

acyloyl anhydride, acetic anhydride, propionic anhydride, and butyricanhydride instead of acetic anhydride, there is obtained a mixture ofcorresponding tetraacyl derivatives including:

N-acetyl-0,0,0-acetylpropionylbutyryldeferoxamine;

N-butyryl-0,0,0-acetylpropionylbutyryldeferoxamine; and

N-propionyl-0,0,0-butyrylpropionylacetyldeferoxamine; or

N-acryloyl-0,0,0-acetylpropionylbutyryldeferoxamine;

N-acetyl-0,0,0-butyrylpropionylacryloyldeferoxamine; and

N-butyryl-0,0,0-acryloylpropionylacetyldeferoxamine

The exact positions of the acyl groups on the hydroxamines is not yetestablished.

EXAMPLE 2 Preparation of N-Acetyl-0,0,0-trihydrogendeferoxamine

(a) N-Acetyl-0,0,0-triacetyldeferoxamine (prepared in Example 1) (10.0g) is taken up in 200 ml of methanol and 500 ml of ether, cooled to 0°C., and the solution is saturated with anhydrous gaseous ammonia. Thereaction mixture is kept at 0° C. for 6 hr, and then at ambienttemperature overnight (about 16 hr). The ammonia-containingmethanol/ether is decanted and the resulting colorless crystalline solidis washed twice with boiling hexane and is dried in vacuum, crude yield8.1 g. After two recrystallizations using methanol/water (60/40), thereare obtained about 7.0 grams of N-acetyl-0,0,0-trihydrogendeferoxamine,m.p. 179°-181°. The infrared spectrum and proton magnetic resonancespectrum are consistent with the structure.

(b) Similarily, proceeding as in Subpart (a) of this Example, butsubstituting a stoichiometrically equivalent amount of:

N-propionyl-0,0,0-tripropionyldeferoxamine;

N-butyryl-0,0,0-tributyryldeferoxamine;

N-valeryl-0,0,0-trivaleryldeferoxamine;

N-octanoyl-0,0,0-trioctanoyldeferoxamine;

N-palmitoyl-0,0,0,-tripalmitoyldeferoxamine; or

N-pentacosanoyl-0,0,0-tripentacosanoyldeferoxamine instead of theN-acetyl-0,0,0-triacetyldeferoxamine, there is obtained thecorresponding

N-propionyl-0,0,0-trihydrogendeferoxamine;

N-butyryl-0,0,0-trihydrogendeferoxamine;

N-valeryl-0,0,0-trihydrogendeferoxamine;

N-octanoyl-0,0,0-trihydrogendeferoxamine;

N-palmitoyl-0,0,0-trihydrogendeferoxamine; or

N-pentacosanoyl-0,0,0-trihydrogendeferoxamine.

EXAMPLE 3 Preparation of N-Acetyl-0,0,0-tripalmitoyldeferoxamine

(a) N-Acetyl-0,0,0-trihydrogendeferoxamine (from Example 2) (6.0 g) issuspended in a solution of 40 ml of water and 50 ml of dioxane. Thewell-agitated suspension is adjusted to pH of 9 using 5N sodiumhydroxide solution. To this mixture is added in 10 ml portions, asolution of 16.5 g of palmitoyl chloride in 60 ml of dioxane. The pH of9 of the mixture is maintained by the addition of a 5N sodium hydroxidesolution after each 10 ml portion of the acyl chloride solution. After40 ml of the palmitoyl chloride solution are added, 50 ml of water and200 ml of chloroform are added to facilitate the mixing of the solution.After the addition of the palmitoyl chloride solution is completed, thereaction mixture is stirred for 1 hr, with periodic monitoring tomaintain a pH of 9. The reaction mixture is then diluted with 150 ml ofwater and 500 ml of chloroform, and centrifuged to separate the phases.The white material present at the liquid interface is discarded. [Theaqueous phase is separated and extracted twice with 250 ml ofchloroform. Essentially no product is obtained upon removal of thechloroform.] The chloroform phase contained a white solid which isremoved using additional centrifugation. The combined chloroform layersare washed twice with saturated sodium bicarbonate solution, twice withsaturated sodium chloride solution, dried over anhydrous sodium sulfate,filtered and evaporated using reduced pressure. About 14 g of a crude,creamy white waxy solid is obtained which is highly soluble inchloroform. The waxy solid was triturated twice with 100 ml of ether toremove the palmitic acid formed. The insoluble residue, 11.8 g, wasrecrystallized from methanol/ethanol (3/1). The solid is air dried toproduce 6.1 g of solid N-acetyl-0,0,0-tripalmitoyldeferoxamine. Thenuclear magnetic resonance spectrum is consistent with the structure.

EXAMPLE 4 Preparation of N-Octanoyl-0,0,0 -trioctanoyldeferoxamine Step1, Schotten-Baumann conditions

(a) Deferoxamine mesylate (6.0 g) is suspended in 50 ml of water and 50ml of dioxane. The suspension is adjusted to pH of 9 using 5N sodiumhydroxide solution with strong agitation. In 10 ml portions, a solutionof 13.0 g of octanoyl chloride in 60 ml of dioxane. The pH of themixture is maintained at 9 by the dropwise addition of the 5N sodiumhydroxide solution. After the addition of 40 ml of the octanoylchloride/dioxane solution, the reaction mixture is treated with 50 ml ofwater and 200 ml of chloroform. The mixture separates into two phaseswhich are agitated strongly. After the addition of all the acid chloridesolution, the reaction mixture is agitated for 2 hr at pH of 9. Thereaction mixture is diluted with 500 ml of water and 1000 ml ofchloroform and the aqueous phase is separated and extracted twice using250 ml portions of chloroform. The combined chloroform phases are washedtwice with saturated sodium bicarbonate solution, twice with saturatedsodium chloride solution and dried using anhydrous sodium sulfate. Thechloroform is removed under reduced pressure, and the waxy residue isdissolved in 500 ml of diethyl ether and hexane was added almost toturbidity. A sticky, granular product weighing 3.8 g is obtained. Theinfrared and proton magnetic resonance spectra are consistent with astructure of N-octanoyl-0,0,0-trioctanoyldeferoxamine.

(b) Similarily, proceeding as in Subpart (a) above, but substituting astoichiometrically equivalent amount of

acetyl chloride;

propionyl chloride;

butyryl chloride;

pivalyl chloride;

valeryl chloride;

isovaleryl chloride;

dodecanoyl chloride;

palmitoyl chloride; or

hexacosanoyl chloride instead of octanoyl chloride, there is obtainedthe corresponding

N-acetyl-0,0,0,-triacetyldeferoxamine;

N-propionyl-0,0,0-tripropionyldeferoxamine;

N-butyryl-0,0,0-tributyryldeferoxamine;

N-pivalyl-0,0,0-tripivalyldeferoxamine;

N-valeryl-0,0,0-trivaleryldeferoxamine;

N-isovaleryl-0,0,0-triisovaleryldeferoxamine;

N-dodecanoyl-0,0,0-tridodecanoyldeferoxamine;

N-palmitoyl-0,0,0-tripalmitoyldeferoxamine; or

N-hexacosanoyl-0,0,0-trihexacosanoyldeferoxamine.

(c) Similarily, proceeding as in Subpart (a) above, but substituting astoichiometrically equivalent amount of

3-chlorobutanoyl chloride;

3-chloroisovaleryl chloride;

10-chlorooctadecanoyl chloride;

10-methoxyoctadecanoyl chloride;

9,10-dichlorooctadecanoyl chloride;

9,10-dibromooctadecanoyl chloride; or

9,10-dimethoxyoctadecanoyl chloride;

instead of octanoyl chloride, there is obtained the corresponding

N-(3-chlorobutanoyl)-0,0,0-tri(3-chlorobutanoyl)deferoxamine;

N-(3-chloroisovaleryl)-0,0,0-tri(3-chloroisovaleryl)deferoxamine;

N-(10-chlorooctadecanoyl)-0,0,0-tri(10-chlorooctadecanoyl)deferoxamine;

N-(10-methoxyoctadecanoyl)-0,0,0-tri(10-methoxyoctadecanoyl)deferoxamine;

N-(9,10-dichlorooctadecanoyl)-0,0,0tri(9,10-dichlorooctadecanoyl)deferoxamine;

N-(9,10-dibromooctadecanoyl)-0,0,0-tri(9,10-dibromooctadecanoyl)deferoxamine;or

N-(9,10-dimethoxyoctadecanoyl)-0,0,0tri(9,10-dimethoxyoctadecanoyl)deferoxamine.

(d) Similarily proceeding as in Subpart (a) above, but substituting astoichiometrically equivalent amount of

acryloyl chloride;

2-butenoyl chloride;

2-pentenoyl chloride;

2-octenoyl chloride;

oleoyl chloride; or

2-pentacosenoyl chloride instead of octanoyl chloride, there is obtainedthe corresponding

N-acryloyl-0,0,0-triacryloyldeferoxamine;

N-2-butenoyl-0,0,0-tri(2-butenoyl)deferoxamine;

N-2-pentenoyl-0,0,0-tri(2-pentenoyl)deferoxamine;

N-2-octenoyl-0,0,0-tri(2-octenoyl)deferoxamine;

N-2-oleoyl-0,0,0-trioleoyldeferoxamine; or

N-2-pentacosenoyl-0,0,0-tri(2-pentacosenoyl)deferoxamine.

(e) Similarily proceeding as in Subpart (a) above, but substituting astoichiometrically equivalent amount of

2-chloroacryloyl chloride;

2-chloropropenoyl chloride;

4-methoxybutenoyl chloride;

2-chlorooctenoyl chloride;

2-chlorooleoyl chloride; or

2-chloropentacosenoyl chloride instead of octanoyl chloride, there isobtained the corresponding

N-2-chloroacryloyl-0,0,0-tri(2chloroacryloyl)deferoxamine;

N-(2-chloropropenoyl)-0,0,0-tri(2chloropropenoyl)deferoxamine;

N-(4-methoxybutenoyl)-0,0,0-tri(4-methoxybutenoyl)deferoxamine;

N-(2-chlorooctenoyl-0,0,0-tri(2-chlorooctenoyl) deferoxamine; or

N-(2-chloropentacosenoyl)-0,0,0-tri(2-chloropentacosenoyl)deferoxamine.

(f) Similarily proceeding as in Subpart (a) above, but substituting astoichiometrically equivalent amount of

cyclopropylacetyl chloride;

cyclobutylacetyl chloride;

cyclohexylpropanoyl chloride;

cyclodecyldecanoyl chloride; or

cyclopentacosanylacetyl chloride instead of octanoyl chloride, there isobtained the corresponding

N-cyclopropylacetyl-0,0,0-tri(cyclopropylacetyl)deferoxamine;

N-cyclobutylacetyl-0,0,0-tri(cyclobutylacetyl)deferoxamine;

N-cyclohexylpropanoyl-0,0,0-tri(cyclohexylpropanoyl)deferoxamine;

N-cyclodecyldecanoyl-0,0,0-tri(cyclodecyldecanoyl)deferoxamine; or

N-cyclopentacosanylacetyl-0,0,0-tri(cyclopentacosanylacetyl)deferoxamine.

(g) Similarily proceeding as in Subpart (a) above, but substituting astoichiometrically equivalent amount of

2-chlorocyclopropylacetyl chloride

4-chlorocyclohexylacetyl chloride

2-chlorocyclopentadecylacetyl chloride;

or 10-(2-chloropentacosanyldecanoyl chloride instead of octanoylchloride, there is obtained the corresponding

N-(2-chlorocyclopropylacetyl)-0,0,0-tri(2-chlorocyclopropylacetyl)deferoxamine;

N-(4-chlorocyclohexylacetyl)-0,0,0-tri(4-chlorocyclohexylacetyl)deferoxamine;

N-(2-chlorocyclopentadecylacetyl)-0,0,0-tri(2-chlorocyclopentadecylacetyl)deferoxamine; or

N-[10-(2-chloropentacosanyl)decanoyl]-0,0,0-tri[10-(2-chloropentacosanyl)decanoyl]deferoxamine.

(h) Similarily proceeding as in Subpart (a) above, but substituting astoichiometrically equivalent amount of

propynoyl chloride;

2-hexynoyl chloride;

2-decynoyl chloride; or

2-pentacosynoyl chloride instead of octanoyl chloride, there is obtainedthe corresponding

N-(propynoyl)-0,0,0-tri(propynoyl) deferoxamine;

N-(2-hexynoyl)-0,0,0-tri(2-hexynoyldeferoxamine;

N-(2-decynoyl)-0,0,0-tri(2-decynoyl)deferoxamine; or

N-(2-pentacosynoyl) -0,0,0-tri(2-pentacosynoyl) deferoxamine.

(i) Similarily proceeding as in Subpart (a) above, but substituting astoichiometrically equivalent amount of

4-chloro-2-butynoyl chloride;

10-chloro-2-decynoyl chloride;

15-chloro-3-pentadecynoyl chloride; or

25-chloro-2-pentacosynoyl chloride instead of octanoyl chloride, thereis obtained the corresponding

N-(4-chloro-2-butynoyl)-0,0,0-tri(4-chloro-2-butynoyl)deferoxamine;

N-10-chloro-2-decynoyl)-0,0,0-tri(10-chloro-2-decynoyl)deferoxamine;

N-(15-chloro-3-pentadecynoyl)-0,0,0-tri(15-chloro-3-pentadecynoyl)deferoxamine;or

N-(25-chloro-2-pentacosynoyl)-0,0,0-tri(25-chloro-2-pentacosynoyl)deferoxamine.

(j) Similarily proceeding as in Subpart (a) above, but substituting astoichiometrically equivalent amount of

benzoyl chloride:

2-naphthoyl chloride; or

1-phenanthroyl chloride for octanoyl chloride, there is obtained thecorresponding

N-benzoyl-0,0,0-tri(benzoyl)deferoxamine;

N-(2-naphthoyl)-0,0,0-tri(2-naphthoyl)deferoxamine; or

N-(1-phenanthroyl)-0,0,0-tri(1-phenanthroy)deferoxamine.

(k) Similarly proceeding as in Subpart (a) above, but substituting astoichiometrically equivalent amount of

4-chlorobenzoyl chloride;

6-methoxy-2-naphthoyl chloride; or

6-chloro-1-phenanthroyl chloride instead of octanoyl chloride, there isobtained the corresponding

N-(4-chlorobenzoyl)-0,0,0-tri(4-chlorobenzoyl)deferoxamine;

N-(6-methoxy-2-naphthoyl)-0,0,0-tri(6-methoxy-2-naphthoyl) deferoxamine;or

N-(6-chloro-1-phenanthroyl)-0,0,0-tri(6-chloro-1-phenanthroyl)deferoxamine.

(l) Similarly, proceeding as in Subpart (a) above but substituting astoichiometrically equivalent amount of

phenylacetyl chloride;

10-phenyldecanoyl chloride; or

2-naphthyldecanoyl chloride; instead of octanoyl chloride, there isobtained the corresponding

N-(phenylacetyl)-0,0,0-tri(phenylacetyl) deferoxamine;

N-(10-phenyldecanoyl)-0,0,0-tri(10-phenyldecanoyl)deferoxamine; or

N-(2-naphthyldecanoyl)-0,0,0-tri(2-naphthyldecanoyl)deferoxamine.

(m) Similarily, proceeding as is described in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thefollowing equimolar mixtures of acyl chlorides:

A. acryloyl chloride, butyryl chloride, benzoyl chloride, and cyclohexylcarbonyl chloride;

B. 2-naphthoyl chloride, 2-butynoyl chloride, phenylacetyl chloride, and4-chlorophenylacetyl chloride; or

C. 3-chloropropionyl chloride, 4-chloro-2-butenoylchloride,4-chlorocyclohexylcarbonyl chloride, and 4-chlorocyclohexylacetylchloride for butyryl chloride.

there is obtained the following mixtures of tetracyldeferoxamines:

A. N-acryloyl-0,0,0-butyrylbenzoylcyclohexyldeferoxamine;N-cyclohexyl-0,0,0-benzoylacryloylbutyryldeferoxamine; andN-benzoyl-0,0,0-butyrylacryloylcyclohexylcarbonyl deferoxamine

B. N-(2-naphthoyl-0,0,0-butynoylphenylacetyl-4-chlorophenylacetyldeferoxamine;N-phenylacetyl-0,0,0-butynoyl-4-chlorophenylacetyl-(2-naphthoyl)deferoxamine;and N-butynoyl-0,0,0-(2-naphthoyl) 4-chlorophenylacetyldeferoxamine; and

C.N-(3-chloropropionyl)-0,0,0-(4-chloro-2-butenoyl)-(4-chlorocyclohexylcarbonyl)(4-chlorocyclohexylacetyl)deferoxamine;N-(4-chlorocyclohexylcarbonyl)-0,0,0-(4-chloro-2-butenoyl)(3-chloropropionyl)(4-chlorocyclohexylacetyl)deferoxamine; andN-(4-chlorocyclohexylacetyl)-0,0,0-(4-chlorocyclohexylcarbonyl)(3-chloropropionyl)(4-chloro-2-butenoyl) deferoxamine.

Products A, B and C also include other possible isomers of the groupsdescribed therein. Also, the position of the acyl groups on the nitrogenand oxygen is not yet known with certainity.

EXAMPLE 5 Preparation of N-Octanoyl-0,0,0-trihydrogendeferDxamine Step 2

(a) N-Octanoyl-0,0,0-trioctanoyldeferoxamine (3.5 g, from Example 4) isdissolved in 250 ml of ether, 100 ml of methanol and saturated atambient temperature with ammonia gas. After stirring for 3 days (about72 hr) at ambient temperature, the reaction mixture is evaporated todryness using reduced pressure, and the solid residue is boiled fivetimes with hexane to remove the octanoic acid amide. The remainingcolorless crystalline product is recrystallized from n-propanol/water(66/34) to give 1.5 g of N-octanoyl-0,0,0-trihydrogendeferoxamine, m.p.185°-187°. The infrared and nuclear magnetic resonance spectra areconsistent with this structure. The product is sparingly soluble inwater and ordinary organic solvents.

(b) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (b) above forN-octanoyl-0,0,0-trioctanoyldeferoxamine, there is obtained thecorresponding

N-acetyl-0,0,0-trihydrogendeferoxamine;

N-propionyl-0,0,0-trihydrogendeferoxamine;

N-butyryl-0,0,0-trihydrogendeferoxamine;

N-pivalyl-0,0,0-trihydrogendeferoxamine;

N-valeryl-0,0,0-trihydrogendeferoxamine;

N-isovaleryl-0,0,0-trihydrogendeferoxamine;

N-dodecanoyl-0,0,0-trihydrogendeferoxamine;

N-palmitoyl-0,0,0-trihydrogendeferoxamine; or

N-hexacosanoyl-0,0,0-trihydrogendeferoxamine.

(c) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (c) above forN-octanoyl-0,0,0-trioctanoyldeferoxamine, there is obtained thecorresponding

N-(3-chlorobutanoyl)-0,0,0-trihydrogendeferoxamine;

N-(3-chloroisovaleryl)-0,0,0-trihydrogendeferoxamine;

N-(10-chlorooctadecanoyl)-0,0,0-trihydrogendeferoxamine;

N-(10-methoxyoctadecanoyl) -0,0,0-trihydrogendeferoxamine;

N-(9,10-dichlorooctadecanoyl)-0,0,0-trihydrogendeferoxamine;

N-(9,10-dibromooctadecanoyl)-0,0,0-trihydrogendeferoxamine; or

N-(9,10-dimethoxyoctadecanoyl)-0,0,0-trihydrogendeferoxamine.

(d) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (d) above forN-octanoyl-0,0,0-trioctanoyldeferoxamine, there is obtained thecorresponding

N-acryloyl-0,0,0-trihydrogendeferoxamine;

N-2-butenoyl-0,0,0-trihydrogendeferoxamine;

N-2-pentenoyl-0,0,0-trihydrogendeferoxamine;

N-2-octenoyl-0,0,0-trihydrogendeferoxamine;

N-2-oleoyl-0,0,0-trihydrogendeferoxamine; or

N-2-pentacosenoyl-0,0,0-trihydrogendeferoxamine.

(e) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (e) above forN-octanoyl-0,0,0-trioctanoyldeferoxamine, there is obtained thecorresponding

N-(2-chloroacryloyl)-0,0,0-trihydrogendeferoxamine;

N-(2-chloropropenoyl)-0,0,0-trihydrogendeferoxamine;

N-(4-methoxybutenoyl) -0,0,0-trihydrogendeferoxamine.,

N-(2-chlorooctenoyl)-0,0,0-trihydrogendeferoxamine; or

N-(2-chloropentacosenoyl)-0,0,0-trihydrogendeferoxamine.

(f) Similarily, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (e) above forN-octanoyl-0,0,0-trioctanoyldeferoxamine, there is obtained thecorresponding

N-cyclopropylacetyl-0,0,0-trihydrogendeferoxamine;

N-cyclobutylacetyl-0,0,0-trihydrogendeferoxamine;

N-cyclohexylpropanoy-0,0,0-trihydrogendeferoxamine;

N-cyclodecyldecanoyl-0,0,0-trihydrogendeferoxamine; or

N-(cyclopentacosanylacetyl)-0,0,0-trihydrogendeferoxamine.

(g) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (g) above forN-octanoyl-0,0,0-trioctanoyldeferoxamine, there is obtained thecorresponding

N-(2-chlorocyclopropylacetyl)-0,0,0-trihydrogendeferoxamine;

N-(4-chlorocyclohexylacetyl)-0,0,0,-trihydrogendeferoxamine;

N-(2-chlorocyclopentadecylacetyl)-0,0,0,-trihydrogendeferoxamine; or

N-[10-(2-chloropentacosanyl) decanoyl]-0,0,0-trihydrogendeferoxamine.

(h) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (h) above forN-octanoyl-0,0,0,-trioctanoyldeferoxamine, there is obtained thecorresponding

N-(propynoyl)-0,0,0-trihydrogendeferoxamine;

N-(2-hexynoyl)-0,0,0-trihydrogendeferoxamine;

N-(2-decynoyl)-0,0,0-trihydrogendeferoxamine; or

N-(2-pentacosynoyl)-0,0,0-trihydrogendeferoxamine.

(i) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (i) above forN-octanoyl-0,0,0-trioctanoyldeferoxamine, there is obtained thecorresponding

N-(4-chloro-2-butynoyl)-0,0,0-trihydrogendeferoxamine;

N-(10-chloro-2-decynoyl)-0,0,0-trihydrogendeferoxamine;

N-(15-chloro-3-pentadecynoyl)trihydrogendeferoxamine; or

N-(25-chloro-2-pentacosynoyl)-0,0,0-trihydrogendeferoxamine.

(j) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (j) above forN-octanoyl-0,0,0-trioctanoyldeferoxamine, there is obtained thecorresponding

N-benzoyl 0,0,0-trihydrogendeferoxamine;

N-(2-naphthoyl)-0,0,0-trihydrogendeferoxamine; or

N-(1-phenanthroyl-0,0,0-trihydrogendeferoxamine.

(k) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (k) above forN-octanoyl-0,0,0-trioctanoyldeferoxamine, there is obtained thecorresponding

N-(4-chlorobenzoyl)-0,0,0-trihydrogendeferoxamine;

N-(6-methoxy-2-naphthoyl)-0,0,0-trihydrogendeferoxamine; or

N-(6-Chloro-1-phenanthroyl)-0,0,0-trihydrogendeferoxamine.

(l) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 4, Subpart (l) above forN-octanoyl-0,0,0-trioctanoyldeferoxamine, there is obtained thecorresponding

N-(phenylacetyl)-0,0,0-trihydrogendeferoxamine;

N-(10-phenyldecanoyl)-0,0,0-trihydrogendeferoxamine; or

N-[10-(2-naphthyl)decanoyl]-0,0,0-trihydrogendeferoxamine.

EXAMPLE 6 Preparation of N-Octanoyl-0,0,0-tributyryldeferoxamine Step 3

(a) N-Octanoyl-0,0,0-trihydrogen deferoxamine [1.5 g, from Example 5(a)] is suspended in a solution of 50 ml of water and 50 ml of chloroform.The well-agitated suspension is adjusted to pH of 9 using 5N sodiumhydroxide solution. To this mixture is added dropwise, a solution of 1.4g of butyryl chloride in 30 ml of chloroform. The pH of 9 of the mixtureis maintained by the addition of a 5N sodium hydroxide solution asneeded. After 20 ml of the butyryl Chloride solution are added 25 ml ofwater and 100 ml of Chloroform are added to facilitate the mixing of thesolution. After the butyryl Chloride solution is all added, the reactionmixture is stirred for 2 hours, with periodic adjustment to maintain apH of 9. The reaction mixture is then diluted with 50 ml of water and200 ml of chloroform and centrifuged to separate the phases. Any whitesolid at the interface is removed and discarded. The chloroform phase iswashed twice with 100 ml of saturated sodium bicarbonate solution andtwice with 100 ml of saturated sodium chloride solution, dried usinganhydrous sodium sulfate, filtered and reduced to dryness using reducedpressure. About 2.0 g of a crude waxy white solid is obtained, which iswashed twice with ether and recrystallized from 60% ethanol. The solidis air dried to produce 1.1 g ofN-octanoyl-0,0,0-tributyryldeferoxamine. The infrared and nuclearmagnetic resonance spectra are consistent with this structure.

(b) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (b) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-acetyl-0,0,0-tributyryldeferoxamine;

N-propionyl-0,0,0-tributyryldeferoxamine;

N-butyryl-0,0,0-tributyryldeferoxamine;

N-pivalyl-0,0,0-tributyryldeferoxamine;

N-valeryl-0,0,0-tributyryldeferoxamine;

N-isovaleryl-0,0,0-tributyryldeferoxamine;

N-dodecanoyl-0,0,0-tributyryldeferoxamine;

N-palmitoyl-0,0,0-tributyryldeferoxamine; or

N-hexacosanoyl-0,0,0-tributyryldeferoxamine.

(c) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (c) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-(3-chlorobutanoyl)-0,0,0-tributyryldeferoxamine;

N-(3-chloroisovleryl)-0,0,0-tributyryldeferoxamine;

N-(10-chlorooctadecanoyl)-0,0,0-tributyryldeferoxamine;

N-(10-methoxyoctadecanoyl)-0,0,0-tributyryldeferoxamine;

N-(9,10-dichlorooctadecanoyl) -0,0,0-tributyryldeferoxamine;

N-(9,10-dibromooctadecanoyl)-0,0,0-tributyryldeferoxamine; or

N-(9,10-dimethoxyoctadecanoyl)-0,0,0-tributyryldeferoxamine.

(d) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (d) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-acryloyl-0,0,0-tributyryldeferoxamine;

N-2-butenoyl-0,0,0-tributyryldeferoxamine;

N-2-pentenoyl-0,0,0-tributyryldeferoxamine;

N-2-octenoyl-0,0,0-tributyryldeferoxamine;

N-2-oleoyl-0,0,0-tributyryldeferoxamine; or

N-2-pentacosenoyl-0,0,0-tributyryldeferoxamine.

(e) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (e) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-2-chloroacryloyl-0,0,0-tributyryldeferoxamine;

N-(2-chloropropenoyl)-0,0,0-tributyryldeferoxamine;

N-(4-methoxybutenoyl)-0,0,0-tributyryldeferoxamine;

N-(2-chlorooctenoyl)-0,0,0-tributyryldeferoxamine; or

N-(2-chloropentacosenoyl)-0,0,0-tributyryldeferoxamine.

(f) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (f) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-cyclopropylacetyl-0,0,0-tributyryldeferoxamine;

N-cyclobutylacetyl-0,0,0-tributyryldeferoxamine;

N-cyclohexylpropanoyl-0,0,0-tributyryldeferoxamine;

N-[10-(cyclodecyl)decanoyl]-0,0,0-tributyryldeferoxamine; or

N-(cyclopentacosanylacetyl)-0,0,0-tributyryldeferoxamine.

Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (g) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-(2-chlorocyclopropylacetyl)-0,0,0-tributyryldeferoxamine;

N-(4-chlorocyclohexylacetyl)-0,0,0,-tributyryldeferoxamine;

N-(2-chloropentadecylacetyl)-0,0,0,-tributyryldeferoxamine; or

N-[10-(2-chloropentacosanyl)decanoyl]-0,0,0,-tributyryldeferoxamine.

(h) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (h) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-(propynoyl) -0,0,0-tributyryldeferoxamine;

N-(2-hexynoyl)-0,0,0-tributyryldeferoxamine;

N-(2-decynoyl)-0,0,0-tributyryldeferoxamine; or

N-(2-pentacosynoyl)-0,0,0-tributyryldeferoxamine.

(i) Similarily, proceding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (i) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-(4-chloro-2-butynoyl)-0,0,0tributyryldeferoxamine;

N-(10-chloro-2-decynoyl)-0,0,0-tributyryldeferoxamine;

N-(15-chloro-3-pentadecynoyl)-0,0,0-tributyryldeferoxamine; or

N-(25-chloro-2-pentacosynoyl)-0,0,0-tributyryldeferoxamine.

(j) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (j) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-benzoyl-0,0,0-tributyryldeferoxamine;

N-(2-naphthoyl)-0,0,0-tributyryldeferoxamine; or

N-(1-phenanthroyl)-0,0,0-tributyryldeferoxamine.

(k) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (k) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-(4-chlorobenzoyl)-0,0,0-tributyryldeferoxamine;

N-(6-methoxy-2-naphthoyl)-0,0,0-tributyryldeferoxamine; or

N-(6-chloro-1-phenanthroyl)-0,0,0-tributyryldeferoxamine.

(l) Similarly, proceeding as is described above in Subpart (a) of thisExample, but substituting a stoichiometrically equivalent amount of thedeferoxamines as prepared in Example 5, Subpart (l) above forN-octanoyl-0,0,0-trihydrogendeferoxamine, there is obtained thecorresponding

N-(phenylacetyl)-0,0,0-tributyryldeferoxamine;

N-(10-phenyldecanoyl)-0,0,0-tributyryldeferoxamine; or

N-(2-naphthyldecanoyl)-0,0,0-tributyryldeferoxamine.

(m) Similarily, proceeding as is described above in Subpart (a) of thisexample, but substituting one half of the stoichiometrically equivalentamount of the following equimolar mixtures of acyl chlorides:

A. acetyl chloride, butyryl chloride, and acryloyl chloride;

B. octanoyl chloride and acryloylchloride; or

C. butyryl chloride and octanoyl chloride for butyryl chloride, there isobtained a corresponding mixture of products including:

A. N-octanoyl-0,0,0-acetylbutyrylacryloyldeferoxamine;N-octanoyl-0,0,0-hydrogenacryloylacetyldeferoxamine; orN-octanoyl-0,0,0-butyrylacryloylhydrogendeferoxamine;

B. N-octanoyl-0,0,0-octanoylhydrogenacryloyldeferoxamine;N-octanoyl-0,0,0-octanoylacryloylhydrogendeferoxamine; orN-octanoyl-0,0,0-dioctanoylacryloyldeferoxamine; and

C. N-octanoyl-0,0,0-butyryloctanoylhydrogendeferoxamine;N-octanoyl-0,0,0-octanoylhydrogenbutyryldeferoxamine; orN-octanoyl-0,0,0-hydrogenbutyryldeferoxamine.

The exact positions of the acyl or hydrogen groups has not yet beenestablished with certainity.

In Examples 7 and 8, the active ingredient inN-acetyl-0,0,0-trioctanoyldeferoxamine. Other compounds of formula I maybe substituted therein.

EXAMPLE 7 Tablet Formation

    ______________________________________                                                         Quantity per                                                 Ingredients      Tablet, mgs.                                                 ______________________________________                                        Active Ingredient                                                                              350                                                          Cornstarch        20                                                          Lactose, spray dried                                                                           100                                                          Magnesium stearate                                                                              2                                                           ______________________________________                                    

The above ingredients are thoroughly mixed, granulated, and pressed intosingle scored tablets.

EXAMPLE 8 Capsule Formation

    ______________________________________                                                         Quantity per                                                 Ingredients      Capsule, mgs.                                                ______________________________________                                        Active Ingredient                                                                              350                                                          Lactose, spray dried                                                                           100                                                          Magnesium stearate                                                                              2                                                           ______________________________________                                    

The above ingredients are mixed and introduced into a hard-shell gelatincapsule.

While the present invention has been described with reference to thespecific embodiments thereof, it should be understood by those skilledin this art that various changes may be made and equivalents may besubstituted without departing from the true spirit and scope of thepresent invention. In addition, many modifications may be made to adapta particular situation, material, or composition of matter, process,process step or steps, or the present objective to the spirit and scopeof this invention, without departing from its essential teachings.

What is claimed is:
 1. A pharmaceutical composition for treating atrivalent metal overload condition or disease in a human being whichcomposition comprises a therapeutically effective amount of a compoundof formula I: ##STR9## wherein R₁ is acetyl and R₂, R₃ and R₄ are eachn-octanoyl.
 2. The pharmaceutical composition of claim 1 wherein the ionis iron (III), aluminum(III), chromium(III) or mixtures thereof.
 3. Thepharmaceutical composition of claim 1 wherein the ion is iron(III). 4.The pharmaceutical composition of claim 1 which is orally effective in apharmaceutically acceptable excipient.
 5. The pharmaceutical compositionof 2 which is orally effective in a pharmaceutically acceptableexcipient.